The present invention relates to easily openable packages each in the shape of a box, and more particularly, packages each comprising an inner box or case and an outer plastic film packing an outer periphery of the inner box and containing an inner content which is easily taken out by opening the plastic film along the outer periphery thereof, and the present invention also relates to a carton tape which is easily torn at its intermediate portion in a width direction thereof without using any cutting device and relates to a carton package using such carton tape.
For example, foods such as chewing gum, sweet jelly beans or the like have been commercially sold in a package in which the food is accommodated in an inner box such as paper and packed or wrapped by an outer packing film formed of such as plastic film. However, a outer packing film is generally formed of the plastic film which cannot be easily torn, and hence, it is difficult for a user to take out the inner content contained in the inner box by easily tearing the outer packing film of the package.
For example, in one aspect, for a package of cigarettes or cigars, in order to easily tear or break an outer packing of the package, a plastic film forming the outer packing is composed of two plastic films and a tear(tearable) tape disposed between these plastic films, and the outer packing is opened by tearing the outer packing along the tear tape.
As mentioned above, the package provided with such tear tape is openable by tearing the outer packing along the tear tape to take out the inner content accommodated in the inner box. However, it is required for the outer packing to have two plastic films having both-surface heat sealable structure to interpose the tear tape therebetween, that is, the outer packing is required to have at least three-layer structure of the plastic films. In addition, positioning of the tear tape is troublesome process. Thus, the plastic film manufacturing process is made complicated, which will increase the manufacturing cost of the package.
The box-shaped package will further include a carton package in another aspect. The carton package is generally composed of a carton body formed by bending or folding a carton so as to provide a box-shaped carton body having an opening which is covered by a pair of lid members integrally formed with the carton body. The lid members entirely cover the opening of the carton body by bending at both side edge portions of the opening so that front end edge portions thereof are mated when bent. When both end edge portions of the lid members are mated at a closed position on the carton body, they are tied to each other by means of a carton tape, thereby fastening the lid members to the closed position. The opening of such carton package is performed by opening the lid members, and when the lid members are opened, it is required to tear the carton tape stuck to the mated end edge portions of the lid members or peel off the carton tape from the lid members.
The carton tape is generally composed of a tape body formed of a paper or synthetic resin film, a binder layer on one surface of a tape body and a release agent layer on the other one surface thereof. The carton tape is wound up around a core member and is cut into a piece having a predetermined width when used. Such carton tapes have relatively large tearing (i.e. rupture) strength, which differ from each other due to the difference of the tape materials, and hence, the carton tapes have structure not to be easily torn or cut.
The tearing strength of the carton tape is determined by the tension strength of the tape material itself, and accordingly, when the tension strength is made small for easily tearing the carton tape, it is impossible to sufficiently function as the carton tape, and on the contrary, when the tension strength thereof is made strong for eliminating such defect, it will be required to use a certain cutting means for cutting the carton tape.